Umbrella anchor



FIG. 1 is a perspective view of an umbrella anchor embodying my design, the dotted line showing of an umbrella is for illustrative purposes only and forms no part of the claimed design;

FIG. 2 is an enlarged side elevational view of the umbrella anchor of FIG. 1;

FIG. 3 is a top plan view of the umbrella anchor of FIG. 2; and,

FIG. 4 is a bottom plan view of the umbrella anchor of FIG. 2. 

The ornamental design for an umbrella anchor, as shown. 